Previously, flowmeters have been supplied factory pre-calibrated i.e. the components of the flowmeter system, including excitation coils, amplification circuitry and control circuitry are calibrated at the time of manufacture, both individually and when assembled together to form the flowmeter system. The calibration of the amplification circuitry and control circuitry is typically performed at room temperature. However, the operating temperature of the flowmeter may differ markedly from room temperature, and therefore the flow measurements obtained will exhibit systematic errors due to miscalibration. Additional errors in the flow measurements are also introduced by the ageing of the components.